Martin Truex Jr believes Hendrick Motorsports' strong performance at Chicagoland Speedway could have been a one-off in the NASCAR Cup Series.
Hendrick's Alex Bowman earned his first career win in the Cup Series on Sunday as all four of the team's drivers finished 11th or higher in the 400-mile race in Chicago.
Three of Hendrick's four drivers - Bowman, Jimmie Johnson and William Byron - also took turns leading the race, combining to lead 107 of the 267 laps.
It came in contrast to a season dominated by Joe Gibbs Racing, which had won 10 of the first 16 races, with team-mates Truex and Kyle Busch tied for the most series wins with four apiece.
Asked after Sunday's race if he felt Hendrick's strength was purely in that race or a new longer-term trend, Truex said: "I think it's just one race.
"You look at these things and you come to these tracks now with this [aero] package and every track is just so different.
"I can't stress it enough how different it is.
"You only get two 50-minute practices and we came here, and we were totally lost for the first whole practice and then two-thirds of the second practice and, if we had another 30 minutes, we could have been so much better.
"It's one of those things where all these tracks are so different, and they want just a different package all together that the first time here is hard to hit it.
"Clearly, [Hendrick Motorsports] hit it out of the park because they were fast right off the truck."
Sunday's race was a struggle for the JGR cars as Busch tagged the wall early in the race and ended a lap down in 22nd.
Truex overcame a slow start to finish ninth, while Denny Hamlin had two pit road penalties and finished 15th.
Erik Jones got the best result for JGR with a seventh-place finish and the team led just six laps.
Truex was also asked if he felt Hendrick's engines had made gains in their performance, since the second-place driver, Kyle Larson, also used an HMS engine.
"It's so hard to tell engine-wise," Truex said. "I feel like we've been a little off on the straightaways all year long and it shows up qualifying.
"We qualify 10th to 20th on these types of tracks so we definitely have a little bit to learn there. "When our cars go through the corners good, we're as fast as anyone.
"I don't know, there are so many things you can work on with these cars nowadays, it's hard to know exactly what to do."